Nvidia 515.76 was superseded by 515.76+really.515.65.01, and is, therefore, not available in the archive. The dependency is correct, since allowing you to install the modules from 515.76 when user-space is really from 515.65.01 will break things badly.
https:/ /bugs.launchpad .net/ubuntu/ +source/ nvidia- graphics- drivers- 515/+bug/ 1996890/ comments/ 3
I think the root cause is same with lp:1996890 .
Nvidia 515.76 was superseded by 515.76+ really. 515.65. 01, and is, therefore, not available in the archive. The dependency is correct, since allowing you to install the modules from 515.76 when user-space is really from 515.65.01 will break things badly.